Couriers are marked on the map as a red-colored moneybag. The Couriers hold a musket and run around in circles. If they see you, they run the otherway and shout "Stay away from me!" Simply chase after them and tackle them down. There is no way for them to spawn so just try to stay in the busy parts of New York and Boston.

There's various types of hiding places throughout the game. Try to find one that is near a building, then run around and attract the guards. Run back and Eagle dive into the Haystack to kill them. You could also Whistle. Another tactic is to go to Sequence 9, Missing Supplies, and just keep restarting the checkpoint after you get in the haystack and kill two guards.

Trigger Open conflict with gurads and then run away. When the indicators of the enemy turn gray, Connor can then hide in a Hiding spot (using bushes, haystacks, or blending, or sitting on benches) until the threat subsides.

See Original Gamer for tips on the minigames. If you want to play them legitimately, Checkers or Bowls is probably your best bet. If you just want to speed through this use a web-based game to quickly win at Nine Men's Morris.